Thursday, August 13, 2009
Necrotizing Soft Tissue Infection
It started as a small perianal abscess. She didn't seek medical attention, hoping it would just go away. The swelling increased, the pain worsened. She started getting dizzy and nauseous and lightheaded and one night passed out after going for dinner with her family. When I saw her in the ER she was frankly septic and in extremis. Antibiotics and fluids were commenced. I rushed her to the OR.
Fournier's gangrene is a devastating condition. The only hope for cure is rapid, definitive surgical debridement. The CT above suggests the degree of gas gangrene extension in the gluteal and peri-rectal soft tissue spaces. There's nothing fancy about this surgery. You cut and debride until all the necrotic fat and skin and muscle is gone. It leaves a horrible wound. Sometimes you have to divert stool with a colostomy to facillitate clean wound care post-operatively.
Here's the thing. When I was called, I was told I had a patient "to see in the morning" regarding a perianal abscess. I thought, OK. But then I checked the computer at home and saw her WBC count was over 35K. Routine perianal abscesses don't give you white counts that high. So I had them run her through the scanner as I was driving in. The key thing with any necrotizing soft tissue infection (NSTI) is getting the patient to the OR ASAP. And you have to be able to identify those patients who are at high risk for NSTI. Here's some key indicators to assess:
1) Extreme leukocytosis (anything over 20K ought to make you nervous)
2) Hyponatremia (Sodium levels less than 135 strangely enough are almost universally seen with NSTI's. My patient presented with a sodium of 123)
3) Hypotension (well duh, sepsis)
4) Appearance of skin (look for bullae, purplish discoloration, desquamation of skin, etc)
5) Crepitus on exam (anaerobic bacterial production of gas in the subcutaneous tissues)
6) Extreme pain, seemingly out of proportion